Definitions of unsaturated:

• adjective:   (of color) not chromatically pure; diluted

  Example: "An unsaturated red"

• adjective:   used of a compound (especially of carbon) containing atoms sharing more than one valence bond

  Example: "Unsaturated fats"

• adjective:   not saturated; capable of dissolving more of a substance at a given temperature

  Example: "An unsaturated salt solution"